1. Field of the Invention
The present invention concerns a two-spool tape cartridge in which a flexible, elastic drive belt contacts the tape on the tape spools and whereby movement of the belt causes movement of the tape between the spools.
2. Description of the Prior Art
The belt driven cartridge of U.S. Pat. No. 3,692,255, issued to Von Behren and assigned to the assignee of the present invention, has been very successfully utilized to interface with computers where rapid acceleration and deceleration of the tape are required. In the cartridge there disclosed, a magnetic recording tape is convolutely wound on two tape spools and is bidirectionally driven between the spools by an endless flexible belt in frictional contact with the tape on both spools. The endless flexible belt is wrapped around and driven by a capstan within the cartridge, which capstan is in turn driven by a motor drive roller which is external to the cartridge and is a portion of a recording/playback tape recorder mechanism into which the cartridge is inserted. The motor drive roller engages the capstan by means of an access opening provided in a wall of the cartridge.
During operation of the cartridge, a static electrical charge is built up on the capstan by frictional contact between the motor drive roller and the capstan. If this static electrical charge is not dissipated, a sudden discharge may result which may cause erroneous signals in the electronics of the tape recorder mechanism.
The static charge problem may be alleviated by manufacturing the capstan of a conductive material such as metal or an electrically conductive polymer such as acetal resin containing carbon. The static charge will then either relocate and neutralize itself throughout the body of the capstan or be conducted to a grounded portion of the cartridge or tape recorder mechanism.
Unfortunately, to produce the capstan of metal is too expensive and carbon-filled acetal resin exhibits poor wear characteristics. Capstan wear is particularly noticeable at the areas of contact between the rotating capstan and its mounting pin and the capstan and surfaces of the cartridge. This wear results in looseness of the capstan relative to its mounting pin and particles which may interfere with the operation of the cartridge or the tape recorder mechanism.